Mechanisms of passive potassium influx in corn mitochondria

Journal Article · Thu Jan 01 00:00:00 EST 1981 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.68.2.267· OSTI ID:5403354

Fluegel, M J; Hanson, J B

Corn mitochondria in 100 millimolar KCl show accelerated passive swelling upon addition of uncoupler. This unusual response has been compared with swelling produced by valinomycin, tripropyltin, and nigericin. It is concluded that the driving force for swelling lies with the chloride gradient and a high P /sub cl/:P/sub k/ ratio, the chloride influx creating a negative membrane potential. The action of uncoupler is to facillitate K/sup +/ influx via the endogenous H/sup +//K/sup +/ antiporter. The antiporter is active over the pH range 6 to 8, is not sensitive to mg/sup 2 +/ concentration, and is not inactivated by aging. It is not clear why corn mitochondria show this exceptional activity of the H/sup +//K/sup +/ antiporter in K/sup +/ influx. It is speculated that during isolation the antiporter may be exposed or activated, and that it contributes to cyclic K/sup +/ transport and high State 4 respiration rates.

• Research Organization: Univ. of Illinois at Urbana-Champaign, IL (United States)
• DOE Contract Number: AC02-76EV00790.A005
• OSTI ID: 5403354
• Journal Information: Plant Physiol.; (United States), Vol. 68
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
MITOCHONDRIA
PERMEABILITY
SWELLING
POTASSIUM
UPTAKE
CATIONS
HYDROGEN
MAGNESIUM
MAIZE
PH VALUE
POTASSIUM CHLORIDES
ALKALI METAL COMPOUNDS
ALKALI METALS
ALKALINE EARTH METALS
CELL CONSTITUENTS
CEREALS
CHARGED PARTICLES
CHLORIDES
CHLORINE COMPOUNDS
ELEMENTS
GRAMINEAE
GRASS
HALIDES
HALOGEN COMPOUNDS
IONS
METALS
NONMETALS
ORGANOIDS
PLANTS
POTASSIUM COMPOUNDS
551000* - Physiological Systems